The present invention relates generally to fully automated systems and methods for operating industrial equipment, such as automated semiconductor manufacturing (fab) facilities and, more particularly, to a micrologistics tracking system for an automated fab.
The efficiency of a manufacturing enterprise depends, in part, on the quick flow of information across its complete supply chain. Off-the-shelf (OTS) enterprise resource planning (ERP) systems were developed and utilized for handling product planning, purchasing, supplier interactions, and customer service and soon gained widespread acceptance. Though useful, these ERP systems were not designed to manage the day-to-day plant-floor operations. Historically, it has been common practice for manufacturers to purchase commercially available Manufacturing Execution Systems (MES) or build their own plant-floor control systems. For example, most semiconductor manufacturers or fabricators (also referred to as “fabs”) purchase commercially available MES's or use some form of “home-grown” MES for tracking production logistics, work-in-process (WIP), equipment status, quality, inventory, process controls, etc.
More recent advancements in shop-floor activities include the automation of production equipment, material processing, material control systems, and the integration of all these systems and applications with the host MES. Automating manufacturing processes for certain industries presents many challenges. Unlike the automotive industry, which employs standard assembly line processing techniques, the manufacture of semiconductor materials generally involves non-linear processing techniques. For example, a 300-mm semiconductor fab involves a complex and lengthy back and forth route in which wafers revisit numerous repetitive levels back through process tools while measurements and feedback of measurements are taken. Automating such complex routes requires a great deal of sophistication in its underlying technology.
In addition, Automated Material Handling Systems (AMHS) were developed to move and track material carriers (also referred to as FOUPs or Front Opening Unified Pods and reticle pods) that are routed through a manufacturing facility or bay. These carriers can also be reduced pitch FOUPs, or any other type of wafer carrier, reticle carrier, or durable used in the manufacture of semiconductors. AMHS subsystems include stockers (also referred to as material storage and retrieval systems), interbay transport devices, and intrabay transport devices. Interbay transport devices move carriers from one stocker to another as well as between bays, while intrabay transport allows movement of a carrier directly to the production equipment either from a stocker or from another production equipment in the bay. Automated interbay and intrabay transport vehicles are often more generally referred to as automatic guided vehicles (AGVs), rail guided vehicles (RGVs), or any type of overhead transport/overhead hoist transport (OHT), and overhead vehicles (OHVs). Software used for implementing AMHS activities includes material control system (MCS) software, which manages the automation of transportation and storage of manufacturing materials.
Notwithstanding the integration of AMHS, MCS software and MES features in current fabs, present tracking capabilities provide only limited information regarding micrologistics (detailed) events being carried out in the fab. For example, in a conventionally generated history of fab lots and equipment, the report information may only include information related to start and stop times for manufacturing operations performed on the work-in-process material lots. However, this information does not relate any data, for example, concerning movement of the lots between operations or storage information. Accordingly, it would be desirable to provide a methodology for providing a more meaningful quantification of the events associated with the flow of product through the automated fab environment.